Device and method for pneumatically feeding a feeding chute

ABSTRACT

A device is provided for feeding fiber material into a textile machine, comprising a horizontal transport channel (10), a feeding chute (2) branching vertically downward from the transport channel (10), an air-collecting chamber (3) separated by an air-permeable intermediate wall (9) from the feeding chute (2) connected with the transport channel (10), the air collecting chamber (3) being provided with a closable blow-off opening for discharging the flow of transport air, and a fiber transport device (18) at the lower end of the feeding chute (2), wherein at least one blow-off opening (6) is arranged at the lower end of the air-collecting chamber, alternately suddenly blowing off or shutting off the flow of transport air (7).

BACKGROUND OF THE INVENTION

This invention relates to a device for pneumatically supplying fiberflocks, e.g. cotton, synthetic fiber material, etc. to a chute or thelike, wherein via a feed conduit, the fiber material is conveyed bymeans of transport air, comprising an air collecting chamber separatedby an air-permeable vertical intermediate wall from the feeding chuteconnected with the transport channel, the air-collecting chamber beingprovided with a closable blow-off opening for discharging the flow oftransport air, and a method for feeding fibers into textile machines bydeflecting a mixture of fibers and transport air into a feeding chute,separating the transport air from the fiber material in a feeding chuteequipped with an air-permeable intermediate wall, blowing off thetransport air from an air collecting chamber arranged behind theair-permeable intermediate wall, and supplying the fiber material fromthe lower end of the feeding chute.

Such devices are used, for example, for carding machines in order tosupply a rather uniform compacted mat of material to the machines. Indoing so, the fibers are conveyed in pipelines in a mixture of fibermaterial and transport air and filled into the feeding chutes associatedwith the textile machines by deflecting the flow of transport air.

In supplying fiber material to a chute, it is important that the fibermaterial is uniformly distributed over the width of the chute when it isdischarged from the pneumatic feed line and that the fiber material inthe feeding chute is uniformly piled over the width and depth thereof.In general, transport air of the pneumatic feed is discharged at onewall surface of the feeding chute. To this effect, one longitudinal wallof the feeding chute is either permeable or it contains correspondingapertures. However, it may happen that fiber material more or lessadheres to the air-permeable wall through which transport air shall getout, so that the release of the transport air is impaired with aresultant disadvantageous effect for the filling density of the feedchute. The way in which the dropped fiber flocks are distributed in thefeeding chute is merely accidental. If the fiber material caught by theperforated wall of the feeding chute and having a more or less longresidence time at the screen surface during the evacuation of transportair exceeds a specific weight of mass, it drops by overweight from thescreen surface. However, such events are irregular and beyond control.The piling of fibers in the chute is substantially accidental.

According to German Patent 33 15 909, it has been known for a device,producing a mat of fiber flocks comprising a substantially verticalchute of a continuous rectangular cross section in the upper part ofwhich ends a feed line for fiber flocks, while the lower chute endincludes a means extending over its width for extracting the fibers as amat, that a plurality of scanning points distributed over the width ofthe fiber mat is provided for detecting the mat density. Said measuringpoints are connected via a control means and a corresponding number ofelements provided at various points of the chute for changing the airflow prevailing at said points in the chute. The measuring points may bepedal troughs. Such an arrangement is very involved. Air flow isinfluenced subsequently, i.e. after the mat has left the feed means overa considerable path length.

In a known feeding device for fiber material (European Patent 0 176668), a feeding chute is disposed below the pipeline, which is separatedfrom an air-collecting chamber by an air-permeable intermediate wall.The air-permeable wall has its upper end provided with an openingthrough which the transport air, separated from the fiber material atthe intermediate wall, may be supplied to a waste air line. The sectionof the passage of the opening can be varied by means of a pivotableflap. A pair of rolls is arranged at the end of the feeding chute forfeeding the fiber material from the feeding chute to the successivemachine.

In doing so, the opening at the upper end of the air-collecting chamber,which is variable in the degree of opening and which can also be shutoff, serves for regulating the supply of fiber material from the pipe tothe feeding chute by the rate of the transport air discharged. In theextreme case, i.e. with the opening shut, no fiber material can fallinto the feeding chute, at least in theory, since the flow of transportair is not deflected into the feeding chute because of thepressure-tight closure of the air-collecting chamber and the feedingchute. In such a feeding chute arrangement, there is no vibration of thefiber material contained in the feeding chute, so that there is nolevelling of the height of the stack of fiber material over the width ofthe feeding chute, and, therefore, the weight load and the unit pressureon the lowest fiber layer in the feeding chute differ, which results ina non-uniformly compacted fiber mat being supplied to the successivemachine.

It is the object of the invention to provide a device of the initiallymentioned type wherein a maximum levelling of the fiber material overthe width of the device is achieved.

It is a further object of the invention to design and configure afeeding chute having a permeable wall surface for discharging transportair in such a way that, without a positively operating control means,the fiber material is piled directly in a substantially uniform densityover the width of the chute.

SUMMARY OF THE INVENTION

This invention substantially relates to a random opening and closingcontrol upon the discharge of the transport air from the air-collectingchamber without a control program being effective directly orindirectly. It has been found that an optional change of opening andclosing operating for the discharge of the transport air allows toautomatically adjust normal air conditions in the feeding or fillingchute. Probable troubles during the piling of the fiber material in thechute are eliminated automatically by the opening and closing control ofthe transport air during its exit out of the air-collecting chamber,subject to the speed at which the change of closing and opening isperformed during the exit of the transport air. Thus, the inventive ideais realized in the random opening and closing of the shut-off memberconcerned. In this way, the passage openings to the closedair-collecting chamber, from which the transport air is discharged, arekept free, so that the cross section of the feeding chute is kept freefrom obstructions and the like caused by the fiber stock. Thus, adistribution of the fed fiber stock over the width of the chute may beobtained together with an effective unification of the fiber densitywithin the chute. Control devices that are necessary only in case of anirregular piling and distribution of the fiber material in the feedingchute, are not needed at all.

Due to such a configuration of the chute, a distribution of the fedfiber material over the chute width and an effective unification of thefiber density may be achieved in the chute. In fact, the distribution ofthe fiber material over the chute width is equalized at least roughlyand directly in the chute itself. It is not necessary to provide aspecial control means responsive to measuring points at the mat. The airflow effect is not only used for equalizing the piling of the fiberflocks over the width of the chute, but one also benefits directlytherefrom for compacting purposes without additional control means.After all, an opening and closing control is used with the discharge ofthe transport air from the air-collecting chamber without the need ofincluding a program.

According to another feature of the invention, the housing forming theclosed collecting chamber may be subdivided by a vertical wall or thelike, the housing parts being provided with a transport air dischargecontaining a closing member. Preferably, the closing members at the twohousing parts may be opened and closed alternatively, thus obtaining acertain pumping effect only by the leaping distribution of air flows inthe chute.

Due to another embodiment of the invention, the housing forming theclosed air-collecting chamber may be divided by vertical walls to obtaina predetermined number of housing parts, each housing part beingprovided with a discharge containing the closing member. Again, adetermined time control need not be provided for the closing member, butit will do that the change of closing and opening is realized without aprogram over the width of the chute.

If transport air is prevented from being discharged in a housingsection, the fiber material caught at the wall drops therefromdownwardly, so that normal air conditions may prevail again.Irregularity of opening and closing control of the closing members isaccompanied by the unexpected result that the fiber material may bepiled uniformly without any troubles over the width and depth of thechute, with a resultant substantially uniform density of the fibermaterial in the feeding or filling chute.

In the embodiment of FIGS. 5 to 7, the fiber flocks in the feeding chuteare compacted to a high degree in the upper area of the feeding chute bythe flow of transport air flowing through them and, in combination witha pulsing vibration in the feeding chute, they are levelled over thewidth of the device with respect to their filling level such that afiber mat supplied to the successive machine at the lower outlet of thefeeding chute has a high uniformity with respect to the fiber densityover its entire width and length. Alternately shutting and opening theblow-off opening in the air-collecting chamber causes a pulsation thatalso prevents a sticking of the fibers to the air-permeable intermediatewall and, thus, a clogging of the intermediate wall. In the shut-offphase, the air flowing into the air-collecting chamber is hinderedabruptly in escaping via the blow-off opening, so that a stagnatingpressure occurs in the air-collecting chamber that is also effective inthe feeding chute via the intermediate wall. The compacting effect inthe upper part of the feeding chute, closed on all sides, isintermittently interrupted by the stopped flow of transport air,whereby, supported by the stagnating pressure in the air-collectingchamber and the feeding chute, the stack of fiber flocks in the feedingchute is momentarily lifted. In this way, a compression and a pulsingvibration are generated alternately, causing a levelling of the stack offiber material over the entire width of the device.

It is an essential advantage of the device according to the presentinvention that it is of a simple construction that can be produced atlow cost, further providing a low probability of failure.

It may be provided to divide the air-collecting chamber vertically andorthogonally to the feeding chute into two chambers by at least oneair-impermeable separating wall and to provide at least one closableblow-off opening for each chamber at the lower ends thereof.

Dividing the air-collecting chamber into chambers has, for example, theadvantage that upon a shut-off of the respective blow-off openings noinstantaneous pressure compensation can occur over the entire width ofthe air-collecting chamber and the feeding chute, whereby the pulsingvibration is increased.

It is provided in one embodiment to arrange the blow-off openingslaterally at the chambers. Without great constructional effort, thelateral arrangement of the blow-off opening permits the connection ofsuction channels with which the transport air may be supplied, forexample, to the suction means of a carding machine.

It may also be provided to arrange the blow-off openings in the bottomof the chambers. Arranging the blow-off openings in the bottom of theair-collecting chamber, in turn divided into chambers, has the advantagethat the flow of transport air is not interrupted before the lower endof the feeding chute.

Preferably, it is contemplated that a control means controls thealternating shut-off and opened phases of the blow-off openings in anoverlapping manner. As an effect of the overlapping control, no flow oftransport air is blown from the chambers of the air-collecting chamberat all for a short time, whereby an increased stagnating pressure and,thus, a stronger pumping effect are generated.

The intermediate wall may consist of a meshed screen. Due to the strongpumping effect from the air-collecting chamber, the fibersadvantageously do not get hooked in the intermediate wall, even if ameshed screen is used as the intermediate wall.

It is provided in an embodiment that the wall of the feeding chuteopposite the air-permeable intermediate wall is elastically supportedand movable in the horizontal direction transversal to the feedingchute. Thereby, the pumping effect can be additionally increased incombination with overlapping shut-off phases of adjacent blow-offopenings, the wall of the feeding chute causing a mechanical vibrationof the fiber material contained in the feeding chute.

BRIEF DESCRIPTION OF THE DRAWINGS

The construction designed to carry out the invention will be hereinafterdescribed, together with other features thereof.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawingsforming a part thereof, wherein an example of the invention is shown andwherein:

FIG. 1 is a schematic view of a feeding or filling chute constructedaccording to the invention;

FIG. 2 is a cross section along line II--II in FIG. 1;

FIG. 3 is a cross section of a filling chute in a modified embodiment,schematically illustrated;

FIG. 4 is a further embodiment of the feeding or filling chute with aplurality of subdivisions of the housing provided in the chute;

FIG. 5 is a perspective view of a further embodiment;

FIG. 6 is a cross section of the feeding device of FIG. 5; and

FIG. 7 is a view of the feeding device of FIG. 5 with the rear wallpartly cut away.

DESCRIPTION OF A PREFERRED EMBODIMENT

As evident from the embodiment of FIGS. 1 and 2, due to a transportchannel 10 above the feeding or filling chute 2, the fibre material isconveyed pneumatically into chute 2, at the lower end of which take-offrollers 18a and 18b may be set up. For the escape of the transport airby which fiber material is supplied to chute 2, one wall of the latteris totally or partly provided with a permeable intermediate wall 9 whichis perforated or otherwise adapted to be air-permeable. Within the areaof the permeable intermediate wall 9, a housing 8 is preset which servesas an air-collecting chamber 1 for the transport air to be discharged.The housing 8 includes a piece 7 with a blow-off opening 6 for the exitand discharge of the transport air, said blow-off opening 6 beingprovided with a closing member 15 that may consist of a slide, a valve,a flap or the like. The drawing shows a slide 13 adapted to bereciprocated by a piston cylinder unit 14 so that, in case of anadvanced slide, the blow-off opening 6 is closed, while, with the slide11 in withdrawn position, the blow-off opening 6 is open.

By a constant opening and closing movement of the closing member 15 atthe blow-off opening 6 of the transport air, air flow in chute 2 may beeffectively influenced. In case of an opened closing member 15, air 16flows through the permeable intermediate wall 9 into the collectingchamber 8 and out of the blow-off opening 6. As a result, fiber flocksmay be induced to more or less adhere to the permeable intermediate wall9 until the fiber accumulation has grown to an extend at which it dropsby its own weight. A uniform depositing of the fed fiber material inchute 2, as well as a uniform distribution over the width of the chuteand the density of the fiber column will be considerably affected thisway. If the closing member 15 locks blow-off opening 6, the fibermaterial does not tend any longer to adhere to the permeableintermediate wall and will be piled up uniformly in chute 2 by means ofthe transport air flow. This is applicable to a natural discharge oftransport air, but also to an air discharge supported by suction or thelike. A steady opening and closing of blow-off opening 6 will cause apulsating effect of the flow of the transport air in the chute. From thebeginning, interfering influences during the uniform distribution andsetting of fiber flocks in the chute are excluded. A natural uniformityof distribution of fibre flocks in the chute is obtained.

In case of the embodiment of FIG. 3, the housing 8' prefixed at theintermediate wall 9 is subdivided by a partition wall 17 so that aseparate blow-off opening 6a or 6b is assigned to each closed housingportion with chambers 4 and 5, said blow-off openings 6a and 6b for thetransport air being provided with separate closing members 15a or 15b,to each of which an independent driving means 14a or 14b is assigned.Also in said arrangement, the closing members 15a and 15b may beoperated by a control means 22 at an irregular cycle. Troubles normallyexisting in the chute during the evacuation of the transport air areavoided. Preferably, the closing members at chambers 4 and 5 are adaptedto be closed and opened alternatively to obtain a certain pumping effectwith the air flow to be discharged. Within the area of the chute inwhich the discharge of transport air is stopped, the air flow has acompacting effect on the fiber material column, said effect changingfrom one area to the other, thus ensuring automatically a uniformpulling and compacting effect of the fiber material in the chute.

In case of the embodiment of FIG. 4, the chute is subdivided into anupper section 2a and a lower section 2b, the measure of the inventionbeing provided for the upper section 2a. Housing 8" preceding thepermeable intermediate wall 9 of the upper section 2a, is for instancesubdivided into four housing parts 8a, 8b, 8c, 8d with chambers 4a-4d,each part being provided with a separate blow-off opening 6a, 6b, 6c, 6dfor the transport air, of which each blow-off opening includes anautomatically movable closing member 15a, 15b, 15c, 15d, for instance inthe form of slides and, as shown in FIGS. 1 to 3, contains independentdriving means. The closing member may be a flap adapted to movevertically to the exit surface of the discharge for the transport air.Use may be made as well of simple valve means. The different closingmembers may be moved in total or partly on and off independently of eachother. It is also possible to maintain a specific sequence so that theclosing members are moved on and off in consecutive order or with anoptional change. A constant change of flow direction of the transportair in the feeding chute is caused this way, so that the desireduniformity of the pile of fiber flocks in the feeding chute is supportedaccordingly. Measuring devices over the width of the discharged mat fortesting its quality are unnecessary. The front side of the housing orhousing parts may be transparent, thus allowing to observe by view theoperation of the closing members. The size of the housing parts isdictated by the width of the filling chute. As a matter of fact, thehousing may be arranged at the lower chute portion rather than at theupper portion thereof, or, if necessary, not only at the upper but alsothe lower chute portion.

The device for feeding fiber material into a textile machine, asillustrated in FIG. 5, has a horizontally extending transport channel10, through which fiber material, included in a mixture of fibers andtransport air, is transported to a plurality of feed devices. A feedingchute 2 into which at least a part of the mixture of fibers andtransport air is directed, thereby filling the feeding chute 2 withfiber material, branches vertically downward from the transport channel10.

In the embodiment of FIG. 5, the transport channel 10 has a rectangularsectional shape. However, other sectional shapes of the transportchannel are usable in combination with the present feed device.

The feeding chute 2 is separated from an air-collecting chamber 1,extending substantially over the entire width and height of the feedingchute 2, by an air-permeable intermediate wall 9, preferably of meshedwire. The upper and/or the lower end of the intermediate wall may havean air-impermeable portion.

By virtue of the air-permeable intermediate wall 9, the mixture offibers and transport air is separated after the fibers have beencompacted in the upper portion of the feeding chute 2, the flow oftransport air reaching the air-collecting chamber 1 via the intermediatewall 9.

The air-collecting chamber 1 may be separated by an air-impermeableseparating wall 3 or, deviating from the illustration in FIG. 5, it mayalso be divided several times vertically and transversally to theintermediate wall 9. The flow of transport air separated from thefibers, thus flows, as illustrated in the Figures, into two separatedchambers 4, 5 of the air-collecting chamber 1. In FIG. 5, the separatingwall is arranged in the center between the side walls 11, 12, anotherdivision of the air-collecting chamber 1 also being possible, e.g. in aratio of 1/3 to 2/3, in order to balance, for example, the distributionof air into the two chambers 4, 5 due to the flow conditions.

In the lower portion of the air-collecting chamber 1, a blow-off opening6 is provided in the respective side walls 11, 12 of the chambers 4, 5that may be suddenly shut and opened. The embodiment is provided with anactivatable piston-cylinder unit 14 that can suddenly open or close theblow-off openings by means of a lid-like closing member 15. It isessential in this regard that a sudden pressure relief is caused in thechambers 4, 5 by opening the blow-off openings and that there is a rapidpressure build-up upon closing the blow-off openings 6. By virtue ofsuitable means, the blow-off openings 6 are opened and shut almostwithout inertia. The cross sectional shapes of the blow-off openings arenot limited to circular openings as shown in the embodiment of the FIGS.5 to 7.

Deviating from FIGS. 5 to 7, the blow-off openings 6 can be provided inthe bottom 8 of the chambers 4, 5 preferably near the intermediate wall9, in order to largely avoid a deflection of the flow of transport airwhen opening or closing the blow-off openings 6.

The lower portion of the intermediate wall 9 may have an air-impermeablestrip in order to prevent the flow of transport air penetrating into thefeeding chute 2 from being relieved at once via the lower opening of thefeeding chute 2. Correspondingly, the blow-off openings 6, when arrangedin the side walls, may be arranged on the level of the lower end of theair-permeable section of the intermediate wall 9.

A further possibility is to reduce the air-collecting chamber 1 and,correspondingly, the air-permeable intermediate wall 9 relative to theheight of the feeding chute, so that a portion of the feeding chuteprotrudes upward and downward beyond the air-collecting chamber 1 at theupper and/or the lower end.

A feed gap 17, tapered in a funnel-like manner, is provided at the lowerend of the feeding chute 2, which compacts the fiber material once moreprior to its being supplied to the successive machine. The supply to thesuccessive machine can be effected directly from the feeding chute 2.The successive machine may be, for example, an opening/cleaning machineor, due to the high degree of uniformity of the discharged fiber web, acarding machine or a further feed shaft. FIGS. 5 to 7 illustrate atransport device in the form of a doffer roller 18 that causes anadditional compacting of the discharged supply web together with thefunnel-shaped feed gap.

The blow-off openings 6 are alternately opened and shut for periods offrom 2 to 5 seconds in the respective chambers 4, 5, the piston-cylinderunits 14 being controlled such that both blow-off openings 6 aretemporarily closed for a period of less than 1 second. Upon closing theblow-off openings 6 in the respective chambers, the downward directedflow of transport air is no longer discharged through the blow-offopenings, whereby a stagnating pressure occurs in the lower part of theair-collecting chamber and the feeding chute. The stack of fibermaterial contained in the feeding chute 2 is relieved because of thelacking compression by the flow of transport air and is raisedtemporarily with support of the stagnating pressure, whereby the fibersin the feeding chute 2 are vibrated rhythmically according to theshut-off and blow-off phases.

Since the closing controls for the blow-off openings 6 overlap at leastpartly with regard to the shut-off phase, whereby a stagnating pressureis created in both chambers 4 and 5, the rear wall 19 of the feedingchute 2 that is in parallel to the intermediate wall 9 pulses in ahorizontal direction according to the pressure build-up in the chambers4 and 5 and in the feeding chute 2, so that an additional mechanicalvibratory effect is generated by the vibrations of the rear wall.

In order to increase these vibrations of the rear wall 19 and to therebyincrease the vibratory effect thereof, the wall may be supported in theframe of the feeding device by suited elastic means 20.

By means of the pneumatic and mechanic vibration, the density of thematerial is levelled and compacted in the best possible way over thewidth of the feeding chute 2. The density of the discharged fiber webcan be varied by means of the control for the opening and shut-offperiods of the blow-off openings by varying the frequency of thevibration of a corresponding control of the closing mechanisms. In doingso, one may also vary the overlapping phases.

The pulsation in the air-collecting chamber and in the feeding chute hasa self-cleaning effect for the intermediate wall 9, so that a meshedscreen may be used as the intermediate wall.

Due to the pumping effect, a meshed screen may be used as theintermediate wall 9, since the fibers cannot clog the meshed screen.

The control of the closing device for the blow-off openings 6 may alsobe performed with the help of sensors 21a and 21b. For example, theshut-off phase for the blow-off opening of a chamber could be initiatedupon the occurrence of a certain flow speed in the chambers 4, 5, andthe opened phase could be initiated upon reaching a certain dynamicpressure or upon detecting that the dynamic pressure has exceeded itsmaximum.

While a preferred embodiment of the invention has been described usingspecific terms, such description is for illustrative purposes only, andit is to be understood that changes and variations may be made withoutdeparting from the spirit or scope of the following claims.

What is claimed is:
 1. A device for pneumatically feeding fiber flocks,to a feeding chute, wherein, via a transport channel, the fiber materialis conveyed by means of a flow of transport air comprising:anair-collecting chamber, an air-permeable vertical intermediate wallseparating said air-collecting chamber from said feeding chute and fromsaid transport channel, said air-collecting chamber having a closableblow-off opening for discharging the flow of transport air, and meansconstantly opening and closing the blow-off opening during the feedingoperation creating a pulsing action of the flow of transport air in thefeeding chutes whereby a more nearly uniform distribution of fiberflocks is achieved.
 2. The structure set forth in claim 1, including ahousing subdivided into a plurality of said chambers by a verticalpartitioning wall, each having a blow-off opening containing a closingmember.
 3. The structure set forth in claim 2 wherein the blow-offopenings are opened and closed alternately.
 4. The structure set forthin claim 1 including a housing forming the closed air-collecting chambersubdivided by vertical walls to obtain a predetermined number ofchambers and wherein each chamber is provided with a blow-off openingcontaining a closing member for the flow of transport air.
 5. Thestructure set forth in claim 4 wherein said means constantly opens andcloses the blow-off opening at a predetermined cycle.
 6. A device forpneumatically feeding fiber flocks, to a feeding chute, wherein, via atransport channel, the fiber material is conveyed by means of a flow oftransport air, comprising:an air-collecting chamber separated by anair-permeable vertical intermediate wall from the feeding chuteconnected with the transport channel; said air-collecting chamber beingprovided with at least one closeable blow-off opening for dischargingthe flow of transport air; at least one blow-off opening arranged at alower end of the air-collecting chamber, alternately suddenly blowingoff or shutting off the flow of transport air; means constantly openingand closing the blow-off opening creating a pulsing action of the flowof transport air in the feeding chute, and means for setting the fillinglevel of the fibers for normal operation to a height that is higher thanthe upper edge of the air-permeable portion of the intermediate wall;whereby a more nearly uniform distribution of fiber flocks is achieved.7. The structure set forth in claim 6, wherein the air-collectingchamber is divided into chambers vertically and orthogonally withrespect to the feeding chute by at least one air-impermeable separatingwall, and each chamber has at least one closable blow-off openingarranged at the lower end of the chambers.
 8. The structure set forth inclaim 6 wherein said blow-off openings are arranged in the bottom ofsaid air-collecting chambers that extends on the level of a lower end ofsaid feeding chute.
 9. The structure set forth in claim 6, wherein acontrol controls the alternating shut-off and blow-off phases of saidblow-off openings in an overlapping manner such that all said blow-offopenings are closed at the same time during an short overlapping phase.10. The structure set forth in claim 6, wherein the wall of said feedingchute facing said air-permeable intermediate wall is supportedelastically and is movable transversal to said feeding chute in ahorizontal direction.
 11. The structure set forth in claim 6, whereinsaid intermediate wall has an end provided with an air-impermeableportion extending over the entire width of said feeding chute.
 12. Thestructure set forth in claim 6, wherein said feeding chute projectsbeyond said air-collecting chamber at at least one end.
 13. A method forfeeding fibers into textile machines comprising the steps of:directing amixture of fibers and transport air into a feeding chute; separating aflow of transport air from the fiber material in a feeding chuteequipped with an air-permeable intermediate wall; supplying the fibermaterial from the lower end of the feeding chute; compacting the fibermaterial contained in an upper portion of the feeding chute closed onall sides, by means of said flow of transport air; constantly blowingoff and shutting off the flow of transport air at the lower end of theair-collecting chamber creating a pulsing action of the flow oftransport air in the feeding chute; and alternately vibrating the fibermaterial contained in the feeding chute during the blow-off and shut-offphases.
 14. The method set forth in claim 13 wherein said flow oftransport air is alternately blown off or shut off at at least twospaced locations.
 15. The method set forth in claim 14 wherein theperiods for the alternating shut-off and blow-off actions last between 2and 5 seconds.
 16. The method set forth in claim 14 wherein the step oftiming the overlapping time of the shut-off phases of said adjacentchambers comprises setting the time periods for less than 1 second. 17.The method set forth in claim 14 comprising the step of shutting off theflow of transport air upon reaching a predetermined flow velocity of thetransport air to be discharged.
 18. The method set forth in claim 14comprising the step of blowing off the flow of transport air when amaximum value of dynamic pressure is exceeded after the shut-off.